Wednesday, June 29, 2016

The sun was almost sinking into the sea, since the coast is oriented a bit too much towards the south. I'm in Southern California for family matters (of a happier kind), and had the opportunity to watch the sunset from out on Balboa Pier. It's always fascinating to watch waves from the back side, and they were particularly rough tonight. It was beautiful. I can't help but hear the words of one of the Eagles' finest songs, "The Last Resort". This especially after spending weeks exploring the wild corners of the Hawaiian Islands, followed by a trip through the urban nightmare of Los Angeles. The beaches around Balboa are almost entirely artificial, having been extensively altered around a century ago. The houses are lined up almost wall to wall, and there isn't much of a natural feel at all. And yet, at the right moment the beauty shines through. The lyrics I selected below are all the property of the Eagles (RIP Glenn Frey).

She heard about a place people were smilin',They spoke about the red man's way, how they loved the landAnd they came from everywhere to the Great DivideSeeking a place to stand or a place to hide

Down in the crowded bars out for a good time,Can't wait to tell you all what it's like up thereAnd they called it paradise, I don't know whySomebody laid the mountains low while the town got high

Then the chilly winds blew down across the desert,Through the canyons of the coast to the MalibuWhere the pretty people play hungry for powerTo light their neon way and give them things to do

Some rich man came and raped the land, nobody caught 'em,Put up a bunch of ugly boxes and, Jesus, people bought 'emAnd they called it paradise, the place to be,They watched the hazy sun sinking in the sea

Who will provide the grand design, what is yours and what is mine?'Cause there is no more new frontier, we have got to make it hereWe satisfy our endless needs and justify our bloody deedsIn the name of destiny and in the name of God

And you can see them there on Sunday morningStand up and sing about what it's like up thereThey called it paradise, I don't know whyYou call some place paradise, kiss it goodbye

Tuesday, June 28, 2016

The answer is easy: clouds. This whole post is a temper tantrum, a tantrum that resulted from the fact that we were on the Big Island of Hawai'i, the site of the biggest mountain on planet Earth, for nine days a few weeks ago. Despite repeated opportunities, my students never had a clear view of Mauna Loa, the volcano that covers more than half of the island. It was a rainy stretch of weather, so the best we ever got were brief peeks, kind of like watching an old-fashioned feather boa dance. So in response, I've drawn from the Geotripper archives to find pictures of Mauna Loa from earlier trips. Very sunny trips.

Mauna Loa from the Mauna Kea Road near the Onizuka Center

Clouds are not the least bit unusual on the slopes of Mauna Loa and Mauna Kea, the two highest peaks on the planet (as measured from the sea floor; of the two, Mauna Kea is slightly higher). The Hawaiian Islands lie in the path of the trade winds most of the year, and as the moist air masses rise against the gentle slopes of the massive shields, they cool and condense into clouds. Hilo is pretty much the wettest city in the United States, with more than 100 inches of rain each year. Oddly enough, an atmospheric inversion layer limits cloud formation to the lower slopes of the volcanoes. It's been more than once that I've left Hilo in a rainstorm only to find crystal clear skies up on the mountain (but not so much last week!). Exceptions, like earlier this month, happen when storm fronts come through. In winter, snow is not a rare occurrence on the high peaks.

Mauna Loa from the Mauna Kea Road above the Onizuka Center

Oceans have a lot to do with the fact that no one gets to see the entirety of Mauna Loa. It is the biggest mountain on the planet, as well as the biggest volcano (although the Tamu Massif may be more voluminous), but it rises of the floor of the Pacific Ocean, with around 17,000 feet hidden beneath sea level. A bit less than 14,000 feet rises above the waves. It depresses the sea floor another five miles, so the mountain could actually be said to be 56,000 feet high. It has a volume of 15,000-19,000 cubic miles.

Sunset on Mauna Loa from Mauna Kea. The brown air is vog from the eruptions at Kilauea on the other side of the mountain.

The volcano began erupting perhaps 700,000 years ago, and became an island around 400,000 years ago. It's hard to confirm since the older lava flows are hidden deep beneath the younger ones. The oldest exposed lavas (at the Ninole Hills) are about 200,000 years old. The giant shield continues to be very active, with 33 eruptions since 1843. The last eruption was in 1984, making this quiescent period the longest in recorded history (contrast that with the continuous eruptions at nearby Kilauea that started in 1983). The lava from the 1984 eruption came uncomfortably close to Hilo.

Mauna Loa from South Point, the imaginatively named southernmost point in the United States.

The gentle slopes of the volcano belie the true immensity of the mountain. To hike from the shoreline to summit is to simulate a trip from the tropics to the Arctic Circle. The slopes above 4,000 feet are among the most important bird habitat in the nation. Hawai'i is a gigantic open laboratory of evolution and the many native species have been decimated by environmental disruptions caused by the arrival of humans and their pigs, goats, rats, and mongooses. Even worse was the arrival of mosquitoes in the 1870s, as they are a vector for transmitting avian malaria. The native birds had no immunity. The mosquitoes can't thrive in the cooler conditions above 4,000 feet, so the mountains are an island within an island, providing sanctuary for the remaining survivors.

Mauna Loa looks almost insignificant in the morning light from Hilo Bay (below), but the summit is around forty miles away. The mountain is gigantic, and dangerous. And we barely got to see it earlier this month. But we knew it was there. We were surrounded by its flows in Hilo, at Hawai'i Volcanoes National Park, at South Point, and at Kona, a drive that took us 120 miles!

Sunday, June 26, 2016

The southeast coast of the Big Island of Hawai'i is a barren blasted land. One can blame it on the lack of rain, but though it is arid, rainfall is plentiful enough to support forests nearby. One only needs to look up the Holei Pali to know right away what the problem is: it's ground zero for the basalt flows emanating from the Kilauea shield complex. These slopes have been covered repeatedly by eruptions, most recently from 1969-75, and during the ongoing eruption that began in 1983. As we will see, each eruption is a paradox of creation and destruction.

The pali, or cliff, belies the description of a shield volcano with gentle slopes. It turns out that the southeast slope of Kilauea is sliding slowly into the sea, and the cliffs are actually giant fault scarps. To most people, "faults" means earthquakes, and there have been some powerful events in this area, including a 7.9 magnitude quake in 1868, and a 7.2 magnitude tremor in 1975 that killed two people.

We were headed down Chain of Craters Road in Hawai'i Volcanoes National Park on the second day of our recent journey. The class, a hybrid course covering geology and anthropology, was having a first look at some of the archaeological sites on the Big Island, and as we looked around, it was hard to imagine living in this strange and ever-changing landscape. There is no development along the road, and yet, if you come across old maps, you will find a string of place names along the route: Kalapana Garden, Waha'ua Heiau, Royal Gardens, the Queen's Bath, the Black Sand Beach of Kaimu, and a national park visitor center. They are all gone now, buried in basalt lava flows. It's a tough land.

A section of the old Chain of Craters Road buried by lavas in the 1969-74 Mauna Ulu eruptions.

And yet, people have lived here, and for hundreds of years. Despite the lack of water and soil, despite a lack of coastal access, there are hundreds of archaeological sites that have not yet been buried beneath the advancing lava flows. The original Hawaiians were Polynesian voyagers, probably from the Marquesas Islands, 2,500 miles to the south (although legends speak of an earlier race of people, the Menehune). The timing of their arrival is debated, with estimates ranging from 1,700 to 800 years ago. Aside from rich fishing along the shorelines, there was little food for the colonizers, but they brought their own plants and animals to assure their survival: taro, breadfruit, banana, coconut, as well as pigs (pua'a) and chickens (moa), and unfortunately, rats. We checked out a small village site that was partially buried in the 1969-74 eruptions (below), and then headed to the Pu'u Loa Petroglyph Trail.

The arrival of humans on the islands heralded huge changes for the native plants and animals. For millions of years, the flora and fauna had evolved in isolation, and had few defenses to the effects of the grazing of pigs and the predation of rats. The first wave of human colonization resulted in extinctions or vast declines in the populations of native plants and animals, especially the birds.

What we know of the culture of the first Hawaiians comes from oral traditions, historical writings since European contact, and archaeological investigations of the older sites. More information comes from linguistic analysis of the Hawaiian dialect. To me, the amateur, the most fascinating hints of the past come from the intersection of humans with the rock: petroglyph art. The barren coastal plain at Pu'u Loa has the largest collection of petroglyphs on the island, with at least 23,000 individual carvings.

A relatively level trail crosses 0.75 miles of the basalt flows to the petroglyph site, where a boardwalk protects many of the carvings. Our ranger guide led us farther up the slopes to another field as well. The rock carvings carry a tremendous amount of religious and cultural significance, especially in a society that did not have written records (although oral histories are extensive).

I try to imagine what a revelation the Big Island was to the first Hawaiians. The Polynesians may or may not have had a cultural memory of volcanism, but the Marquesas Islands were not one of the active chains where they would have seen volcanoes in action. What did they think of these blasted plains of lava in a place where plants should have been growing? What did they think as they witnessed their first eruptions, and perhaps the destruction of some of their villages? It must have been a profound and terrifying experience.

We reached the end of Chain of Craters Road and had a look at the Holei Sea Arch and the rugged coastline. This was not the stereotypical white sandy beach with surfers and high-rise hotels. It was a violent battleground between ocean waves and volcanic rock. The lava flows destroy human developments, but they also create new lands, providing a balance to the constant destruction brought about by by the raging sea.

Disclaimer: This is NOT happening right now! These pictures are from 2009.

Pu'u O'o is the invisible volcano on the Big Island. It's been the center of eruptive activity for much of the last thirty years, but there are very few easily accessible localities from which it can be seen. One pretty much has to fly over it to see anything at all.

We are continuing a journey to understand the Hawai'i That Was, seeking to understand the islands as they were before European contact, and before Polynesians arrived a thousand years earlier. Understanding the islands requires an understanding of volcanism. The islands exist only because of lava, and in observing active eruptions we see the origins of each of the Hawaiian islands.

Getting closer to the Pu'u O'o cone. Notice the lack of surface flows of lava. It's almost all beneath the surface in lava tubes.

There is a huge unknown involved with every journey to the islands. The volcanoes refuse to follow a schedule, and feel no need to be convenient to the itineraries of visitors. It's true that Kilauea has been erupting continuously now for more than thirty years, so there is a fair chance that the eruption will continue for the foreseeable future. Then again, the eruption could end tomorrow. There's just no way to know. So, one plans for the possibility, but leaves a lot of alternate activities if lavas aren't visible anywhere.

The location of the lava tube system was obvious. Every so often the roof of the tube would collapse, forming a skylight that emitted steam and other gases.

Kilauea is the sole volcano erupting on the island right now, although Mauna Loa is showing a few hints of possible activity. The lavas are exposed at two localities, at Halemaumau in the Kilauea Caldera (see the previous post), and at the cone of Pu'u O'o on the east rift zone about ten miles away. During the many months that we were planning the trip, Pu'u O'o was pretty much just simmering with no active lava flows since 2014, when the town of Pahoa in the Puna District was briefly threatened (damage was thankfully limited).

So we had a hard decision to make: do we bust the budget on a helicopter flight in hopes of seeing lava flows, though there have been none for more than a year, or do we make other arrangements? We opted to make other choices, which was good because we arrived on the islands during a wet spell, and we probably would have seen little through the rain clouds, although a small lava flow started a week before we arrived. It's now three miles long and approaching the coastal pali (look here for a recent video), but we've been home for nearly two weeks. We just plain missed it.

Looking into the crater of Pu'u O'o, source of the lava flows

The situation was different in 2009, the last time we held a class on the islands. Pu'u O'o had been very active for more than a year, with a broad "delta" and lava tube system feeding basalt into the ocean. We opted for the helicopter flight and were richly rewarded. For one reason or another, I've never collected these pictures together in a blog post.

A rootless shield on the Pu'u O'o lava flow.

The first two photos above show the Pu'u O'o cone and crater from a distance. At various times it has been a more prominent cone, but at other times it collapses. Lava left the cone through a series of lava tubes and flowed southeast towards the coast. Sometimes lava would well up through a skylight, forming a small "rootless shield" like the one in the picture above.

I was surprised, almost disappointed by the lack of "rivers" of lava, but our pilot found a recent breakout, and we saw glowing lava and silvery pahoehoe flows that had formed only hours earlier.

Active lava flows on the slopes below Pu'u O'o. This would have been a real spectacle at night.

The silvery reflective appearance was caused by the formation of a thin film of volcanic glass on surface of the flow. The glass breaks off and degrades quickly, leaving behind the more characteristic dull black or dark gray surface.

A skylight over a lava tube.

If you are having trouble visualizing the scale, realize that we never dropped below 500 feet in altitude. The skylight above is probably 30-40 feet across.

Minutes-old breakouts

Our flight continued over the pali (cliff) and onto the coastal plain. Farther from the vent there were more kipukas, islands of forest that were spared from destruction as the lava flowed by. Kipukas are the seed repositories that would eventually cover these flows with new forests.

And then we reached the coast, where the lava emerged from the lava tubes and plunged into the sea. The union of hot lava and cold seawater was explosive. The lava shattered into black sand on contact.

Occasionally we could see lava through breaks in the clouds of steam.

We flew around, but not through the steam cloud. It is a noxious mix of hydrogen sulfide and acids.

As I went through the pictures much later, I found that one of them gave an end-on view of the entire eruption from Pu'u O'o on the right to the ocean entry on the left (below). The distance between is seven miles (11 kms). It's hard to describe the feeling of seeing the forces of creation and destruction at war with each other. We were seeing the continuing birth of the Big Island. Eventually the fires here will die, but a new island will emerge off to the south (it's already got a name: Lo'ihi. Look for it to appear in a few thousand years).

It's not entirely true to say that we never saw Pu'u O'o on the trip a few weeks ago. There is a spot on Highway 11 near Glenwood Road and the Hirano Store where the cone can be seen. During our reconnaissance before the students arrived, we stopped and had a brief look (below). Of course, once the students were with us we tried again, but it was hidden in the rain.

The Pu'u O'o as of this writing has advanced three miles down the upper slopes of the east rift zone and is approaching the coastal pali. If the eruption keeps up, the flow may once again reach the sea, and once again cover the extension of Chain of Craters Road. After the close call of 2014, the road was rebuilt as an emergency escape route for people in the Puna District. Such are the risks of living on an active volcano.

In the next post, we'll see evidence of a conflict between the gods and humans as they settled the island, a conflict that continues today.

Kilauea is one of the five major shield volcanoes making up the Big Island of Hawai'i. As we found in the last post in this series on the "Hawai'i That Was", Kilauea is the most active of the island's volcanic centers, with an ongoing eruption dating back to 1983. On our first full day on the island, we had a look at the smoking pit of Halemaumau, but in the afternoon, we headed over to Kilauea Iki ("little source of great spewing").

Kilauea Iki from the northeast rim. Pu'u Pua'i is the mound on the right. The steam and gas in the distance is the ongoing eruption of Halemaumau. This picture is from 2009; it was foggy at this point on our recent trip.

Prior to the 15th century, Kilauea Iki was not a crater at all, but was instead a small shield volcano called 'Aila'au. It collapsed in the aftermath of an eruption, forming a pit crater 800 feet deep (the present crater is only half that depth). One of the lava tubes formed in the eruption is today known as Nahuku (Thurston Lava Tube). It is lit, and is an easy walk from Crater Rim Road (good luck finding a parking spot on busy days). Our goal for the day was to hike the north rim of the crater, descend into west end of the crater itself, and then climb the east rim, a distance of about 3 1/2 miles.

If that looks like an abrupt dropoff to the left, it is; it's a sheer 400 foot cliff into the crater.

The trail begins in a phenomenal high altitude rain forest (4,000 feet, ~100"/year) composed mostly of native Ohi'a trees and ferns. On my last trip in 2009, the forest was filled with kahili ginger, an aggressive invasive species. It has pretty flowers, but forms thickets that crowd out the natives. I didn't see any at all this time, although I am sure they are lurking in the forest away from the trail (kudos to the trail crews removing them).

Another serious pair of problems in the native rainforests were the feral pigs and goats. The pigs arrived with the Polynesians over 1,000 years ago. The goats arrived with Captain Cook and his crew, the first Europeans to discover the islands in 1778. Both animals wreaked havoc on the forest. The animals were finally removed by the 1990s, so the forests at Hawai'i Volcanoes are approaching something resembling their original state.

Our first look at the Pu'u Pua'i and the crater interior

The day had been overcast, but as we passed in opening in the forest we could see across the crater to Pu'u Pua'i, a mountain that is younger than I am. The extraordinary eruption that produced this landscape began in November of 1959 as lava started pouring from a rift system on the south side of the Kilauea Iki crater. The eruptions consolidated into a single vent within a few days, and for the next five weeks, spectacular things happened.

Seventeen different times, lava shot high into the air, and the crater filled with millions of cubic yards of simmering basalt. At the end of an eruptive episode, some of the basalt would drain back into the vent, but as the weeks passed by, Kilauea Iki crater filled to a depth of 400 feet (recall the original crater was 800 feet deep). During the latest stages of the eruption, the lava fountain reached a height of 1,900 feet (580 meters), the highest ever recorded in Hawai'i.

In the aftermath of the eruption there was a brand new cinder cone, and a lake of molten lava. During the final draining event, the lake level dropped about fifty feet leaving behind a "bathtub ring" (sciency version: "lava subsidence terrace"). We descended out of the forest, over the bouldery terrace, and into a ghostly barren landscape. After a few minutes we passed the remains of the eruptive vent at the base of Pu'u Pau'i (below).

The eruptive vent of Pu'u Pau'i

From then on, we were walking on a lake of fire. The eruption may have ended in 1959, but a four hundred foot deep lake does not cool all at once. It doesn't take weeks, or even months. It takes decades. Four months after the eruption, the crust was only 9 feet thick! Drilling allowed researchers to track the cooling process. In 1967, the crust was 90 feet thick, and in 1975 it was up to 180 feet (See Hazlett's book for details). The lava lake was more or less solid by the late 1990s, but there is no doubt that it is still very hot down below. Whenever the rain starts (roughly every five minutes, it sometimes seems), steam can be seen rising from fractures in the lake surface (below). Steam rising up the old drill holes is hot enough to scald.

We continued across the surprisingly flat surface of the lava lake. There were pressure ridges and fractures here and there, but the trail was easy to follow, using ahu (cairns, or rock piles).

One of the most astounding things about this lake of fire is the stubbornness with which life seeks to take root. Native Ohi'as are one of the most adaptable trees on the planet. They can form hundred foot high canopies in the native rainforests, but they can also grow in one of the most ghastly environments possible, that of a fresh lava flow. We passed dozens of scraggly bush sized Ohi'as and hundreds of small ferns. Recall that the forest on the rim above is no older than 500 years. In a few centuries (barring new eruptions, which are likely), this barren surface will be a thick forest.

We reached the eastern edge of the crater just as the rain began to pour. The change back to rainforest was abrupt. We climbed four hundred feet up a relatively gentle gradient and found our way to the vehicles. We had crossed the lake of fire and survived!

We never really saw the sun on the day's journey, but when we visited in 2009, we were treated to a gorgeous rainbow as we set off across the crater floor. It was astounding.

If you ever have the chance to visit Hawai'i Volcanoes National Park and want to see a bit of the native environment of the islands (the Hawai'i that was...), this trail is one of your best chances to see what it was like.

About Me

I am a teacher of geology at Modesto Junior College and former president of the National Association of Geoscience Teachers, Far Western Section. I have led field trips all over the western United States, and a few excursions overseas, but my homebase is the Sierra Nevada, the Great Valley, and the Coast Ranges of California.

Ask Geotripper

Is there something about geology that you are curious about? Do you have questions about the scientific aspects of political controversies? I can try to provide a scientist's perspective. Your questions and possible answers could be a springboard to a blog discussion, or they can be private. Anonymity is always assumed. Contact Geotripper at hayesg (at) mjc.edu.

Blooks, Boogers and Bleries

Here are some of the series I've produced for the Geotripper Blog:

The Other California: what to see when you've seen all the really famous places in the Golden State (in progress).Into the Great Unknown: A rafting journey down the Colorado River through the Grand Canyon. The most incredible adventure of my life (so far)!

The Hawai'i That Was: An exploration of the geology, natural history, and anthropology of the most isolated lands on the planet. It's a lot more than beaches, shopping, and palm trees!